Apparatus for bottomhole coring

ABSTRACT

An apparatus for the bottomhole coring of formations during drilling comprising a core bullet holder having a core bullet and positioned within an aperture of a baffle plate located in a drill string. The core bullet holder is also positioned with an aperture of a drill bit to allow exposure of the core bullet to an undrilled sample of the formation. A cartridge is positioned within a cartridge chamber in proximity to the core bullet. A firing pin is located above the cartridge chamber and is driven into the cartridge to fire the core bullet into the formation by a piston slideably positioned within a piston chamber located in the upper portion of the core bullet holder. The piston is engaged by a trigger member which extends through an aperture in the core bullet holder. The trigger member releases the piston when contacted by the baffle plate as the core bullet holder passes through the aperture therein.

United States Patent [191 [11'] 3,807,511 Oliver [45] Apr. 30, 1974 APPARATUS FOR BOTTOMHORE CORING [57] ABSTRACT [75] lnventor: Donald L. Oliver, Houst T x. An apparatus for the bottomhole coring of formations during drilling comprising a core bullet holder having [73] Asslgnee' Servlce C Tulsa a core bullet and positioned within an aperture of a' baffle plate located in a drill string, The core bullet [22] Filed: Nov. 17, 1972 holder is also positioned with an aperture of a drill bit to allow exposure of the core bullet to an undrilled [21] Appl' 307687 sample of the formation. A cartridge is positioned Related US. Application Data within a cartridge chamber in proximity to the core [63] Continuation-impart of Ser. No. 129,493, March 30, bullet A firin'g is located abov? the cartridge 1971 chamber and 1s drlven into the cartridge to fire the I core bullet into the formation by a piston slideably po- 521 US. Cl. 175/4 Sitioned Within a Piston chamber located in the pp 51 v 1m. (:1 E2 lb 49/02 portion of the core bullet holder- The Piston is [58] Field of Search 175/4, 246, 247', 248,58 gaged by a trigger member which extends through an aperture in the core bullet holder. The trigger member [56 Reference's Cited releases the piston when contacted by'the-baffle plate UNITED STATES PATENTS as the core bullet holder passes through the'aperture 2,628,816 2/1953 Mahan 175/4X therein Y 3,172,486 3/l965 Kinley 175/4 Primary ExaminerAlfred R. Guest Attorney, Agent, or Fir mElton F. Gunn 11 Claims, 2 Drawing Figures ago-n51 1 PATENTEWR so. am

SHEET 1 0F 2 PATENTEWRsmsM 3801.511

SHEEI 2 0F 2 Qim APPARATUS FOR BOTTOMHOLE CORING BACKGROUND OF THE INVENTION I This is a continuation-in-part application of my copending application, Ser. No. 129,493, filed Mar. 30, 1971.

The present invention relates to an apparatus for obtaining of a bottomhole core sample. More particularly, the apparatus of the present invention comprises a core bullet with means for imparting the core bullet into the formation, and means for retrieving the encaptured core and core bullet from the wellbore.

A long recognized and desirable method for obtaining reliable information-from the bottom of wellbores during the drilling of a well is the coring of a section of the formation from the wellbore. Core samples are important to drilling in that evaluation of the lithology of the formation being penetrated by the drill bit is afforded the drilling operator while simultaneously providing evidence of the lithology of the formation being drilled for geologic evaluation. It is vital to the drilling operation to obtain information on a current basis so that the drilling operator may adapt procedures to optimumly drill the lithology being penetrated by the drill bit. Although various conventional devices have been utilized to aid in the day-to-day analysis of well drilling (for example, drilling records of pump pressure, torque requirements and analysis of drill bit cuttings produced from the wellbore), no satisfactory teachings have been provided for obtaining untampered sample of the formation through a coring technique without the necessity of removing the drill string and drill bit from the wellbore.

What is required is a bottomhole core to supplement the geological data provided during drilling operations. An apparatus is required for the sampling of formations during drilling and, in particular, the obtaining of a core during the entry of a drilling break for exact determination of the lithology being encountered by the drill bit, without the necessity ofremoving the drill string and drill bit from the wellbore.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an apparatus for obtaining a bottomhole core sample.

It is a further object of the present invention to provide an apparatus whereby a bottomhole core sample may be obtained during a drilling operation.

It is still a further object of the present invention to provide an apparatus wherein a bottomhole core sample may be obtained through the drill string and drill bit without requiring drilling equipment removal from a wellbore.

The present invention accomplishes its desired objects through an apparatus for bottomhole coring from the earths surface through a drill string and drill bit. Broadly, the apparatus comprises a core bullet holder having an outside diameter smaller than the inside diameter of the drill string; a core bullet situtated in the lower portion of the core bullet holder having an outside diameter smaller than the inside diameter of the core bullet holder; and means for projecting the core bullet into the formation ahead of the drill bit. The apparatus additionally includes means for removing the 1 core bullet from the drill bit and drill string.

These, together with various ancillary objects and features which will become apparent to those artisans possessing ordinary skill in the art and as the following description proceeds are attained by the novel apparatus for bottomhole coring, a preferred embodiment shown in the accompanying drawing, by way of example only wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view of the invention shown within a drill string and drill bit;

FIG. 2 is an enlarged fragmentary vertical sectional view of FIG. 1 disclosing means for firing the apparatus for bottomhole coring to encapture a core sample from the wellbore.

DETAILED DESCRIPTION OF THE INVENTION Referring in detail now to the drawings, wherein similar parts of the invention are identified by like reference numerals, thereis seen drill string 20 having drill bit 22 threadably connected thereto, and drill string 20 includes funnel-shaped baffie plate 22 with aperture 24 therein through which core bullet holder 26 passes. Core bullet holder 26 has top 28 with opening .30 and includes an outside diameter smaller than the inside diameter of drill string 20 and aperture 32. Core bullet 35 is situated in a bullet barrel 78 in the lower portion of core bullet holder 26 and has an outside diameter smaller than the inside diameter of core bullet holder 26. Core bullet holder 26 additionally includes cartridge chamber 34 having cartridge 36 positioned in proximity to core bullet 35. Firing pin 38 is situated above cartridge chamber 34 and is in slideable contact with cartridge 36. Piston chamber 40 is located in the upper portion of core bullet holder 26 and has sides 66 defining a plurality of weep holes 68 to aid the flow of fluid within chamber 40 during piston 42 downward movement. Piston 42 is slideably positioned within piston chamber 40 and includes piston head 44 in slideable contact with firing pin 38. Cartridge chamber 34 and piston chamber 40 are removable from core bullet holder 26 for access to cartridge 36 and firing pin 38. Spring 46 is situated between piston 42 and top 28 of core bullet holder 26 and projects piston head 44 into contact with firing pin 38. Stationary coned thrust plate 46 is located between cartridge chamber 34 and core bullet 35 to direct the exhaust gases of cartridge 36 towards core bullet 35. Wire line 48 is connected to core bullet holder 26 and is wrapped around coned thrust plate 46 to allow an even distribution of the wire line as core bullet 35 is projected into the formation (not shown). Wire line 50 is connected to core bullet holder 26 by an assembly of rings and wire lines (generally illustrated as 52) and extends to the surface of the earth.

Piston 42 additionally includes at least one channeled groove 54 situated in the upperportion thereof and is opposite aperture 56 of core bullet holder 26. Trigger member 58 extends through aperture 56 and is pivotally connected at 60 to core bullet holder 26 and engages channeled grooves 54. Core bullet holder 26 additionally includes stoppage member 62 connected above trigger member 58 and extends outwardly therefrom sufficient enough to prevent core bullet holder 26 from continuing through. aperture 24, and provides protection against preactivation of trigger 58 due to lateral movement of core bullet holder 26 as it is lowered in the drill string 20. Piston 42 also additionally includes T-shaped weight member 64 passing through opening 30 and connected to piston 42 to supplement the driving of piston head 44 into firing pin 38 by spring 46.

With continuing reference to the drawings for operation of the invention, there is seen wire line 50 lowering core bullet holder 26 through opening 24 until trigger member 58 is contacted by baffle plate 22 to release trigger member 58 from channeled grooves 54. Spring 46 and weight member 64 subsequently drive piston head 44 into firing pin 38 to fire cartridge 36 and emitting exhaust gases towards core bullet 35 to project core bullet 35 into the formation. Core bullet 35 and core bullet holder 36 may be removed from drill string and drill bit by raising core bullet holder 26 by wire line 50 towards the surface of the earth. Wire line 48 withdraws core bullet 35 from the formation as core bullet holder 26 is continually raised by wire line 50 towards the surface of the earth. While the present invention has been described with reference to particular embodiments thereof, a latiare intended in the foregoing disclosure, and in some instances some features of the invention will be. em-.

ployed without a corresponding use of other features without departing from the scope of the invention as set forth.

I claim:

1. An apparatus for bottomhole coring from the surface of the earth through a drill string and drill bit with an aperture therein which comprises:

a. a core bullet holder having a bullet barrel at the lower end which intercommunicates with a cartridge chamber located above the bullet barrel, said holder having an outside diameter smaller than the inside diameter of the drill string and the drill bit aperture, 7

b. a baffle plate positioned within said drill string, said plate having a conical opening through which said holder passes,

c. means for projecting a core bullet from said barrel when a bullet is contained therein including a firing pin positioned above said cartridge chamber and adapted for slidable contact with a cartridge placed in said chamber, firing pin driving means for driving said pin into a cartridge placed-in said chamber, trigger means for selectively retaining the firing pin driving means above the firing pin prior to firing a cartridge and for. releasing the firing pin driving means when a cartridge is to be fired, and

d. further including means for removing a core bullet from a drill bit and drill string after firing the bullet.

2. The apparatus of claim 1 in which said means for driving said firing pin into a cartridge comprises a piston chamber positioned .in the upper portion of said core bullet holder, a piston having a piston head and slideably positioned within said piston chamber with comprises a first wire line connectible to the upper portion of a core bullet and to the lower portion of said core bullet holder, and a second Wire line connected to said core bullet holder and passing to the surface of the earth.

5. The apparatus of claim 4 wherein said piston 'additionally includes at least one channeled groove situated in the upper portion of said piston, and the said core bullet holder includes an aperture for the trigger means opposite said channeled groove of said piston.

6. The apparatus of claim 5 wherein said means for releasing said means for driving said firing pin into a cartridge comprises a trigger member pivotally con,- nected to said core bullet holder extending th'roughthe trigger means aperture and engaging said channeled groove of said piston.

7. the apparatus of claim 6 wherein said means for firing a cartridge additionally. comprises said trigger member pivoting downwardly upon contact with said baffle plate to release said piston and enabling said spring biased means to drive said piston head into contact with said firing pin to fire a cartridge.

8. The apparatus of claim 7 wherein said core bullet holder additionally includes a stoppage member connected to said core bullet holder above said trigger member and extends outwardly therefrom at a distance sufficient enough to prevent said core bullet holder from continuing through said second aperture of said baffle plate.

9. The apparatus of claim 8 in which said piston additionally includes a weight member passing through said opening and connected to said piston to supplement the driving of said piston head into said firing pin by said spring biased means.

10. The apparatus of claim 9 in which said cartridge chamber and said piston chamber are removeable from said bore bullet holder for access to a cartridge and said firing pin, and said piston chamber in-cludes sides defining a plurality of weep holes to aid the flow of fluid within said piston chamber during said piston downward movement. V

11. The apparatus of claim 10 additionally including a stationary coned thrust plate positioned between said cartridge chamber and said core bullet barrel, said plate having an aperture therein to direct cartridge exhaust gases towards a core bullet, and said first wire line is wrapped around said coned thrust plate to allow an even distribution of said first wire line as a core bullet is projected into the formation. I l 

1. An apparatus for bottomhole coring from the surface of the earth through a drill string and drill bit with an aperture therein which comprises: a. a core bullet holder having a bullet barrel at the lower end which intercommunicates with a cartridge chamber located above the bullet barrel, said holder having an outside diameter smaller than the inside diameter of the drill string and the drill bit aperture, b. a baffle plate positioned within said drill string, said plate having a conical opening through which said holder passes, c. means for projecting a core bullet from said barrel when a bullet is contained therein including a firing pin positioned above said cartridge chamber and adapted for slidable contact with a cartridge placed in said chamber, firing pin driving means for driving said pin into a cartridge placed in said chamber, trigger means for selectively retaining the firing pin driving means above the firing pin prior to firing a cartridge and for releasing the firing pin driving means when a cartridge is to be fired, and d. further including means for removing a core bullet from a drill bit and drill string after firing the bullet.
 2. The apparatus of claim 1 in which said means for driving said firing pin into a cartridge comprises a piston chamber positioned in the upper portion of said core bullet holder, a piston having a piston head and slideably positioned within said piston chamber with said piston head above said firing pin, and spring biased means for projecting said piston head into said firing pin.
 3. The apparatus of claim 2 wherein said spring biased means for projecting said piston head into contact with said firing pin is situated between said piston and said top of said core bullet holder.
 4. The apparatus of claim 3 wherein said means for removing a core bullet from a drill string and drill bit comprises a first wire line connectible to the upper portion of a core bullet and to the lower portion of said core bullet holder, and a second wire line connected to said core bullet holder and passing to the surface of the earth.
 5. The apparatus of claim 4 wherein said piston additionally includes at least one channeled groove situated in the upper portion of said piston, and the said core bullet holder includes an aperture for the trigger means opposite said channeled groove of said piston.
 6. The apparatus of claim 5 wherein said means for releasing said means for driving said firing pin into a cartridge comprises a trigger member pivotally connected to said core bullet holder extending through the trigger means aperture and engaging said channeled groove of said piston.
 7. the apparatus of claim 6 Wherein said means for firing a cartridge additionally comprises said trigger member pivoting downwardly upon contact with said baffle plate to release said piston and enabling said spring biased means to drive said piston head into contact with said firing pin to fire a cartridge.
 8. The apparatus of claim 7 wherein said core bullet holder additionally includes a stoppage member connected to said core bullet holder above said trigger member and extends outwardly therefrom at a distance sufficient enough to prevent said core bullet holder from continuing through said second aperture of said baffle plate.
 9. The apparatus of claim 8 in which said piston additionally includes a weight member passing through said opening and connected to said piston to supplement the driving of said piston head into said firing pin by said spring biased means.
 10. The apparatus of claim 9 in which said cartridge chamber and said piston chamber are removeable from said bore bullet holder for access to a cartridge and said firing pin, and said piston chamber in-cludes sides defining a plurality of weep holes to aid the flow of fluid within said piston chamber during said piston downward movement.
 11. The apparatus of claim 10 additionally including a stationary coned thrust plate positioned between said cartridge chamber and said core bullet barrel, said plate having an aperture therein to direct cartridge exhaust gases towards a core bullet, and said first wire line is wrapped around said coned thrust plate to allow an even distribution of said first wire line as a core bullet is projected into the formation. 